A Review of Black Skin Research: Gloger Rule/Theory Dead or Alive?

Abstract

Unlike various topics of human life that recurringly naggingly preoccupy scholars, black skin tends to be considered by prestigious biology and science publication outlets as a closed and disposed-of topic. The present paper is not one of experiment, but rather the paper is a long-due comprehensive review of black skin scholarship, using a dominant theory of this scholarship, and suggesting newer insights for future research. Known since Antiquity, black skin -- euphemistically called dark sin -- has become the topic of repeated public debate in recent decades. Part of the reason is that although race is believed to be scientifically nonexistent skin color is not. Meanwhile, among the theories explaining black skin, Gloger rule/theory stands out to be the most popular. While multitudes of reviews have examined Gloger theory, few have confronted the theory with the arguments of Gloger himself. This might be because Gloger writings remain untranslated and unknown to English readership. Although Gloger was an ornithologist by profession, his arguments had immense ramifications far beyond the study of birds. The present paper focused on the key arguments of Gloger to present a critical assessment of black skin materials. To this effect, a comprehensive, historical background of Gloger theory was used along with recent research to bring in sharper relief Gloger teachings about skin color. In light of Gloger critiques, it was determined that Gloger theory is no less than inadequate and so is the description of black skin as a product of natural selection. Taken-for-granted theories and resultant arguments of black skin were reversed and paths for future skin color work were proposed. Gloger arguments highlight variability among species and across latitudes.

Toward a Synopsis of the Challenges Facing Mainstream Interpretations of Skin Pigmentation in Humans

“…An interpretation deserving of note here is one in which northern hemisphere is portrayed to be the province of light-pigmented individuals (i.e., Western Europeans) while southern hemisphere represents the homestead of black-skinned peoples, wiping out altogether dark-skinned Innuits and similar Nordic populations. The interpretation is achingly discrepant with the well-documented existence of aboriginal, curled-haired, and black-skinned populations in the Caucasian Mountain (Cibangu, 2022), among others, let alone the marked diversity of peoples in Nordic regions of which Caucasians were/are nothing but a tiny minority.…”

“…(pp. 35-36) However, both the ideas of highest heat in Africa and latitudinal gradation of human pigment were met in the 19th century with stinging massive criticism (see Cibangu, 2022). Although Smith had to soften up his position, his ideas are still attractive to date, further obscuring pigment research/nature (details below).…”

“…Equally, the thesis of fire and cooked meat as long processes brings home the idea of skin pigmentation as a long process by and of itself. Physical activity and resulting alleged argument of eccrine production were found to be impractical in and irrelevant to a savannah or forest setting (Cibangu, 2022).…”

“…Attempts, however, have been recently made to show that this temperature is 3º or 4º below the truth; but Humboldt, in reply still maintains his former opinion. (p. 111) As explained above, Humboldt, the founder of latitudinal gradient diversity and of most instruments for the measurement of latitude and longitude (see more details in Cibangu, 2022), had to repeatedly repudiate misconceptions about equatorial temperatures. One figure of great value for pigment research to be recalled here is German naturalist Constantin Wilhelm Lambert Gloger (1803Gloger ( -1863, who, using data-supported materials, demonstrated the temperatures of equatorial Africa to be much lower than those of North America.…”

“…Still, while reviews have been conducted on the topic (black) pigment (Brancalion, Haase, & Wade, 2022;Caro & Mallarino, 2020;Cibangu, 2022;Solano, 2014, d'Ischia, 2013Jablonski, 2017Jablonski, , 2018Jablonski, , 2021Jablonski & Chaplin, 2017), a follow-up for pigment research has been lacking and important materials along with the challenges leveled from the 19th century onward have gone unnoticed and unconnected, leaving authors with superficial and incorrect approaches toward the issues faced or posed. The most troubling part of the stigma surrounding black pigment is that the stigma is fueled and propagated by highly renowned scholars, with assumingly a (well-intended) given agenda behind.…”